NEW YORK - Hope for a launch of shortened NHL season still remains after league officials and the NHL Players' Association negotiated for more than four hours Wednesday night and agreed to resume bargaining at 10 a.m. Thursday with a federal mediator present.

Scot L. Beckenbaugh of the U.S. Federal Mediation and Conciliation was present for the negotiations that started roughly at 8:15 p.m. Wednesday and finished before 1 a.m. on Thursday.

"I'm not going to get into the details. There was some progress," NHL Commissioner Gary Bettman said. "But we are apart on a number of issues. But as long as the process continues, I am hopeful."

Players had recently voted overwhelmingly to give the NHLPA executive board the option of dissolving the union through a "disclaimer of interest" declaration, but the 11:59 p.m. Wednesday deadline for the authorization passed with the NHLPA not taking that action. NHLPA executive director Donald Fehr wouldn't discuss the issue, calling it an "internal" matter.

"When you disclaim interest as a union, you notify the other side, and we have not been notified," Bettman said. "It's never been discussed, so there has been no disclaimer."

The NHLPA could choose to pursue a disclaimer of interest at a later date. Dissolving the union would open the door for players to sue the NHL through antitrust laws. Both the NFL and NBA players filed "disclaimers of interest" in their last collective bargaining negotiations.

Neither Bettman nor Fehr would discuss the specific bargaining issues. Fehr described Wednesday's sessions as "going back and forth on a lot of different issues."

The bargaining efforts have intensified since last Thursday when the owners made a 288-page proposal. Since then, the players have responded with a proposal, and then the owners came back with another one on New Year's Day. The players responded to that Wednesday afternoon and that led to the night bargaining.

"If you have a river to cross, you got to either build a bridge or do something else," Fehr said.

The league's proposal last week suggested a goal of trying to have a 48-game season launching by Jan. 19. That would require the two sides to reach an agreement by around Jan. 11.

Although the sides are still haggling over a handful of important issues, there does appear to be an urgency on both sides to get a deal done.

It is known that players are very concerned about the new pension plan that has been proposed, particularly how it will be funded.

"The pension plan is a very complicated issue, with a number of variables and a number of issues that have to be addressed by people who carry the title of actuary or pension lawyer," Bettman said. "It's pretty easy to get off track. But that's something that we understand is important to players."

USA TODAY Sports also confirmed that the NHL still wants a $60 million cap in the second year of the deal, and the NHLPA wants a $65 million cap.